NCT03401970

Brief Summary

This is a 2-year randomized controlled trial to test the effect of dietary carbohydrates, both quality and quantity, on changes in internal body fat mass. Up to 250 women and men with obesity are recruited in Bergen, Norway, and randomized to one of the following normo- and isocaloric dietary patterns (same amount of protein, polyunsaturated fatty acids and moderate energy, 2,000 - 2,500 kcal per day): 1) a low-fat high-carbohydrate diet primarily with refined (e.g., flour-based) carbohydrate sources, 2) a low-fat high-carbohydrate diet based on minimally refined (e.g., cellular) carbohydrate sources, and 3) a very-high-fat low-carbohydrate diet.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
150

participants targeted

Target at P75+ for not_applicable

Timeline
Completed

Started Jan 2018

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

August 23, 2017

Completed
4 months until next milestone

Study Start

First participant enrolled

January 3, 2018

Completed
14 days until next milestone

First Posted

Study publicly available on registry

January 17, 2018

Completed
2.3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 20, 2020

Completed
10 months until next milestone

Study Completion

Last participant's last visit for all outcomes

March 24, 2021

Completed
Last Updated

April 26, 2021

Status Verified

April 1, 2021

Enrollment Period

2.4 years

First QC Date

August 23, 2017

Last Update Submit

April 23, 2021

Conditions

Adiposity

Keywords

Body compositionInternal body fatDietary patternDietary carbohydrate

Outcome Measures

Primary Outcomes (1)

  • Change in internal body fat

    Visceral fat mass (cm3) measured by computed tomography (CT) imaging

    Baseline and 6, 12 and 24 months

Secondary Outcomes (28)

  • Change in postprandial insulin

    Baseline and 3, 6, 9, 12 and 24 months

  • Change in postprandial C-peptide

    Baseline and 3, 6, 9, 12 and 24 months

  • Change in postprandial triacylglycerol

    Baseline and 3, 6, 9, 12 and 24 months

  • Change in postprandial area under the curve (AUC) glucose

    Baseline and 3, 6, 9, 12 and 24 months

  • Change in postprandial non-esterified fatty acids

    Baseline and 3, 6, 9, 12 and 24 months

  • +23 more secondary outcomes

Study Arms (3)

Acellular carbohydrate diet

ACTIVE COMPARATOR

Prescribed dietary pattern. Carbohydrates from acellular sources, e.g., refined flour/bakery products, at least 500 grams of fruits/vegetables per day, and a macronutrient composition within typical nutritional recommendations for the general population.

Behavioral: Acellular carbohydrate diet

Cellular carbohydrate diet

EXPERIMENTAL

Prescribed dietary pattern. Carbohydrates from cellular sources, e.g., root vegetables, fruits, whole-grain rice, non-flour grain products, at least 500 grams of fruits/vegetables per day, and a macronutrient composition within typical nutritional recommendations for the general population similar to the acellular carbohydrate diet.

Behavioral: Cellular carbohydrate diet

Low-carbohydrate high-fat diet

EXPERIMENTAL

Prescribed dietary pattern. Energy largely from fat, cellular carbohydrate sources, and otherwise similar food types as in the acellular/cellular carbohydrate diets including at least 500 grams of fruits/vegetables per day.

Behavioral: Low-carbohydrate high-fat diet

Interventions

Acellular carbohydrate dietBEHAVIORAL

Participants will be asked to consume 2,000 - 2,500 kcals, thereof 45 energy percent (E%) carbohydrate (up to 5 E% added sugar), 30 E% fat (10-12 E% saturated fatty acids and 7-10 E% polyunsaturated fatty acids) and 17 E% protein. They will use an original online/smartphone application that provides choices of meals/food combinations/recipes corresponding to their prescribed macronutrient profile and dietary pattern. Participants are asked to complete 3-day dietary records every 14 days throughout the study, and to report any deviations from the planned interventions.

Acellular carbohydrate diet
Cellular carbohydrate dietBEHAVIORAL

Participants will be asked to consume 2,000 - 2,500 kcals, thereof 45 energy percent (E%) carbohydrate (up to 1 E% added sugar), 38 E% fat (10-12 E% saturated fatty acids and 7-10 E% polyunsaturated fatty acids) and 17 E% protein. They will use an original online/smartphone application that provides choices of meals/food combinations/recipes corresponding to their prescribed macronutrient profile and dietary pattern. Participants are asked to complete 3-day dietary records every 14 days throughout the study, and to report any deviations from the planned interventions.

Cellular carbohydrate diet
Low-carbohydrate high-fat dietBEHAVIORAL

Participants will be asked to consume 2,000 - 2,500 kcals, thereof 10 energy percent (E%) carbohydrate (up to 1 E% added sugar), 73 E% fat (30 E% saturated fatty acids and 7-10 E% polyunsaturated fatty acids) and 17 E% protein. They will use an original online/smartphone application that provides choices of meals/food combinations/recipes corresponding to their prescribed macronutrient profile and dietary pattern. Participants are asked to complete 3-day dietary records every 14 days throughout the study, and to report any deviations from the planned interventions.

Low-carbohydrate high-fat diet

Eligibility Criteria

Age20 Years - 55 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Body-mass index (BMI) equal to or above 30 kg/m2 and/or waist circumference equal to or above 102 cm for men and 88 cm for women
  • Weight stable during the last 2 months before start of the study (less than 5 % change in body weight up or down)
  • No known diabetes or consumption of diabetes medication
  • Desire to follow a specified dietary pattern using specific recipes throughout the time of the study period
  • Ability to periodically record food intake using a specially designed app for the study

You may not qualify if:

  • Use of statins and/or diabetes medication
  • Recent surgical or antibiotics treatment during the last 2 months before start of the study
  • Chronic inflammatory bowel disease
  • Serious disease
  • Smoking
  • Pregnancy or breast feeding
  • Alcohol consumption during the study of more than 2 alcohol units per day (1 unit = 15 ml (12.8 g) pure alcohol)

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Forskningsenhet for helseundersøkelser (research unit for clinical trials), Department of Clinical Science, University of Bergen

Bergen, 5021, Norway

Location

Related Publications (3)

  • Jensen C, Sommersten CH, Laupsa-Borge J, Storas I, Valeur J, Mellgren G, Dierkes J, Dankel SN, Lied GA. Quality and quantity of carbohydrates, faecal short-chain fatty acids and gastrointestinal symptoms - results from a randomised, controlled trial (CARBFUNC). Clin Nutr. 2025 Jan;44:54-64. doi: 10.1016/j.clnu.2024.11.041. Epub 2024 Nov 26.

    PMID: 39631208DERIVED

  • Sommersten CH, Gjerde ES, Laupsa-Borge J, Andersen AI, Lawrence-Archer L, McCann A, Hansson P, Raza GS, Herzig KH, Lied GA, Martins C, Mellgren G, Dierkes J, Dankel SN. Relationship between Ketones, Ghrelin, and, Appetite on Isocaloric Diets with Varying Carbohydrate Quality and Amount: Results from a Randomized Controlled Trial in People with Obesity (CARBFUNC). J Nutr. 2023 Feb;153(2):459-469. doi: 10.1016/j.tjnut.2022.12.030. Epub 2022 Dec 29.

    PMID: 36894239DERIVED

  • Sommersten CH, Laupsa-Borge J, Andersen AIO, Fasmer KE, Holmefjord MA, Revheim I, Johannessen KK, Naesheim NT, Storas I, Leikanger T, Amundsen K, Skjerve KL, Lawrence-Archer L, Spjelkavik C, Haldorsen I, Lindseth I, Dierkes J, Mellgren G, Dankel SN. Diets differing in carbohydrate cellularity and amount similarly reduced visceral fat in people with obesity - a randomized controlled trial (CARBFUNC). Clin Nutr. 2022 Oct;41(10):2345-2355. doi: 10.1016/j.clnu.2022.08.028. Epub 2022 Sep 5.

    PMID: 36116147DERIVED

MeSH Terms

Conditions

Obesity

Condition Hierarchy (Ancestors)

OverweightOvernutritionNutrition DisordersNutritional and Metabolic DiseasesBody WeightSigns and SymptomsPathological Conditions, Signs and Symptoms

Study Officials

  • Simon N Dankel, PhD

    University of Bergen

    PRINCIPAL INVESTIGATOR

  • Gunnar Mellgren, MD PhD

    Haukeland University Hospital

    STUDY DIRECTOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

August 23, 2017

First Posted

January 17, 2018

Study Start

January 3, 2018

Primary Completion

May 20, 2020

Study Completion

March 24, 2021

Last Updated

April 26, 2021

Record last verified: 2021-04

Locations

NO(1)